Compendium

May 2013, Volume 34, Issue 5

Published by AEGIS Communications

Thomas Hein, DDS, says advances in composite technology over the years—including improvements in handling, shading, and hardness—have expanded his ability to offer his patients durable esthetic restorations. However, the Colorado private practitioner is especially excited about and eager to share with his colleagues a method using the strength and flowability of Septodont’s N’Durance® Dimer Flow universal composite to quickly restore abfraction lesions without anesthetic or preparation other than etching the enamel and dentin walls.

Hein says he was dissatisfied with earlier approaches to restoring these flexural notches that cause the tooth to become more sensitive and weak, leading to restoration breakdown, and sometimes tooth loss. “The previous approach to treatment was by cutting a notch in the tooth with a bur to hold a putty-type composite filling—thus sacrificing both dentin and enamel and sometimes weakening the tooth further,” he explains.

However, while experimenting with N’Durance Dimer Flow, Hein discovered that by using the existing notch in the tooth and this flowable, adaptable material, he could get it to adhere better without cutting into the tooth and making it weaker.

“This method requires no preparation other than etching, rinsing, and drying, as long as there are two opposing walls notched into the tooth that enable retention of the material,” he says.

The technique he developed begins with adjusting the inevitable occlusal interference, then doing an acid-etch, starting on the enamel margin and wall. After about 10 seconds, the etch is placed in the notch and on the dentin wall and left for an additional 7 to 10 seconds. This is followed by a 20-second rinse.

Next, a prime is painted on the whole preparation, air-thinned, and light-cured; then this prime process is repeated. After this, the bond is placed, thinned with air, and light-cured.

Finally, N’Durance is flowed and worked into the notch to fill where the notch was so it is completely repaired. “The notch is totally eliminated and the surface is perfectly smooth—like nothing ever happened,” says Hein. At this point, he continues, the clinician needs to add a second layer of flowable N’Durance to thicken the facial contour to a cervicle bulge, which protects the gingival margin from food trauma. “This will allow gingival recession to recover from a receded ½-mm sulcus back to a normal 2-mm to 3-mm sulcus.”

The procedure, Hein says, takes one-quarter to one-third of the time previously needed to fill the notch, because it requires no anesthetic and little or no tooth preparation. This, he says, means greater efficiency for the dentist and less discomfort for the patient.

“With N’Durance, clinicians have a material that, due to its flowability, can be worked into a complex notch and achieve better adaption to the tooth. This makes more mechanical retention and requires less tooth preparation,” says Hein. In addition, he says, the material is hydrophobic and polymerizes more completely to become harder than materials previously available, so it lasts longer and adheres better.

The benefits of N’Durance cited by Hein stem mainly from its material composition, a unique mix of dimethacrylate monomers that reduces the shrinkage effect of resin and minimizes the risk of any tissue response and postoperative sensitivity. It is a low-shrinkage, low-toxicity composite that works for both anterior and posterior teeth, he says. Because it is compatible with all bonding systems, it can be used with any self-etch or total-etch bonding agent, and due to its lower volumetric shrinkage, it causes less stress on the tooth–restoration interface, so restorations are more durable.

Available in eight VITA® shades, including, Universal Opaque, Incisal, and Bleach White, N’Durance flowable offers exceptional polishability, and with almost no water uptake, there is no pigment absorption or solubility, ensuring restorations that maintain functional integrity, are color stable, and resist staining.

“The technique came about because of the product—N’Durance flowable composite,” says Hein. “There is more mechanical retention, it adheres better, and it polymerizes harder than any material I’ve used before.”